Recent integration of copper interconnect processes into IC (integrated circuit) manufacturing requires copper terminating chips to be bonded directly on the copper metal pad and circuit boards. The present invention allows the use of conducting polymers to bond copper terminating chips directly on copper substrate or printed circuit boards.
U.S. Pat. No. 5,923,955 to Wong describes a process for creating a flip-chip bonded combination for a first and second integrated circuits using a Ni/Cu/TiN structure.
U.S. Pat. No. 5,891,756 to Erickson describes a method for forming a solder bump pad, and specifically to converting a wire bond pad of a surface-mount IC device to a flip-chip solder bump pad such that the IC device can be flip-chip mounted to a substrate. The method uses a Ni layer over the pad.
U.S. Pat. No. 5,795,818 to Marrs describes a method of forming an interconnection between bonding pads on an integrated circuit chip and corresponding bonding contacts on a substrate. The method uses coined ball bond bumps.
U.S. Pat. No. 5,904,859 to Degani describes a method for applying under bump metallization (UBM) for solder bump interconnections on interconnection substrates. The UBM comprises a Cu, Cu/Cr, Cr multilayer structure.
U.S. Pat. No. 5,767,009 to Yoshida et al. describes a method of reducing cross talk noise between stacked semiconductor chips by the use of a chip on chip mounting structure.
U.S. Pat. No. 5,804,876 to Lake et al. describes a low contact resistance electrical bonding interconnect having a metal bond pad portion and conductive epoxy portion.